But doctors at the University of California, San Diego, are working on an acne vaccine.

The vaccine would block the negative effects of P. acnes, a bacteria on skin that causes acne.

The vaccine is about to go through clinical trials in humans.

I wrote a story on acne for the April issue of Allure, and was shocked to find out that about 50 million Americans are diagnosed with acne every year. That's more than the entire population of Australia or Canada. And you know what's even more surprising? "The incidence of adult female acne is increasing every year," says Joshua Zeichner, an acne specialist and director of cosmetic and clinical research in dermatology at Mount Sinai Hospital in New York. (Case in point: Our executive editor, Danielle Pergament, going on Accutane for the first time at 41.) "And no one really knows why. It's like having a complacent personality versus an argumentative one — histrionic skin fights back against bacteria we're all covered in and breaks out."

The fact that scientists don't know the exact cause of acne explains why there's no real cure for a skin condition that so many of us have. (That 50 million number, by the way, includes anyone who's seeking help for chronic acne, or who gets one pimple a month.)

But things are starting to look up. An acne vaccine that would change the way we approach skin care for ever is in the works. Imagine an entire generation that doesn't know what it's like to touch up concealer before meetings, pray that a new medication will finally clear up their skin, or wake up to scars from past breakouts?

The vaccine targets a protein secreted by acne bacteria. Shutterstock

Inside a lab at the University of California, San Diego, a group of scientists is working to eradicate acne for good. But developing a vaccine for acne has unique complications.

"Acne is caused, in part, by P. acnes bacteria that are with you your whole life — and we couldn't create a vaccine for the bacteria because, in some ways, P. acnes are good for you," says Eric C. Huang, the project's lead researcher. "But we found an antibody to a toxic protein that P. acnes bacteria secrete on skin — the protein is associated with the inflammation that leads to acne." That means the vaccine can block the negative, acne-causing effects of P. acnes bacteria without killing the bacteria themselves.

So far, it's worked on skin biopsies that the researchers collected from acne patients. "The next step is testing it on patients in clinical trials," says Huang. The first phase of those trials, which could take one to two years, will be underway soon.